While many of Bank of America's divisions notched lower first-quarter earnings on a year-over-year basis, its asset and wealth management operation scored a big win.

For anyone wondering whether the Merrill Lynch acquisition will turn out to be good for Bank of America(NYSE:BAC), the bank's first-quarter results should help tilt the needle in the positive direction. There's simply no question that Merrill's thundering herd is starting to pull its weight and fuel Bank of America's bottom line. In the video below, Motley Fool contributor John Maxfield discusses this in further detail, and provides one lesson that all investors can take away from it.